iced_runtime/overlay/
nested.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
use crate::core::event;
use crate::core::layout;
use crate::core::mouse;
use crate::core::overlay;
use crate::core::renderer;
use crate::core::widget;
use crate::core::{Clipboard, Event, Layout, Point, Rectangle, Shell, Size};

/// An overlay container that displays nested overlays
#[allow(missing_debug_implementations)]
pub struct Nested<'a, Message, Theme, Renderer> {
    overlay: overlay::Element<'a, Message, Theme, Renderer>,
}

impl<'a, Message, Theme, Renderer> Nested<'a, Message, Theme, Renderer>
where
    Renderer: renderer::Renderer,
{
    /// Creates a nested overlay from the provided [`overlay::Element`]
    pub fn new(
        element: overlay::Element<'a, Message, Theme, Renderer>,
    ) -> Self {
        Self { overlay: element }
    }

    /// Returns the layout [`Node`] of the [`Nested`] overlay.
    ///
    /// [`Node`]: layout::Node
    pub fn layout(
        &mut self,
        renderer: &Renderer,
        bounds: Size,
    ) -> layout::Node {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            renderer: &Renderer,
            bounds: Size,
        ) -> layout::Node
        where
            Renderer: renderer::Renderer,
        {
            let node = element.layout(renderer, bounds);

            if let Some(mut nested) =
                element.overlay(Layout::new(&node), renderer)
            {
                layout::Node::with_children(
                    node.size(),
                    vec![node, recurse(&mut nested, renderer, bounds)],
                )
            } else {
                layout::Node::with_children(node.size(), vec![node])
            }
        }

        recurse(&mut self.overlay, renderer, bounds)
    }

    /// Draws the [`Nested`] overlay using the associated `Renderer`.
    pub fn draw(
        &mut self,
        renderer: &mut Renderer,
        theme: &Theme,
        style: &renderer::Style,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
    ) {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            layout: Layout<'_>,
            renderer: &mut Renderer,
            theme: &Theme,
            style: &renderer::Style,
            cursor: mouse::Cursor,
        ) where
            Renderer: renderer::Renderer,
        {
            let mut layouts = layout.children();

            if let Some(layout) = layouts.next() {
                let nested_layout = layouts.next();

                let is_over = cursor
                    .position()
                    .zip(nested_layout)
                    .and_then(|(cursor_position, nested_layout)| {
                        element.overlay(layout, renderer).map(|nested| {
                            nested.is_over(
                                nested_layout.children().next().unwrap(),
                                renderer,
                                cursor_position,
                            )
                        })
                    })
                    .unwrap_or_default();

                renderer.with_layer(layout.bounds(), |renderer| {
                    element.draw(
                        renderer,
                        theme,
                        style,
                        layout,
                        if is_over {
                            mouse::Cursor::Unavailable
                        } else {
                            cursor
                        },
                    );
                });

                if let Some((mut nested, nested_layout)) =
                    element.overlay(layout, renderer).zip(nested_layout)
                {
                    recurse(
                        &mut nested,
                        nested_layout,
                        renderer,
                        theme,
                        style,
                        cursor,
                    );
                }
            }
        }

        recurse(&mut self.overlay, layout, renderer, theme, style, cursor);
    }

    /// Applies a [`widget::Operation`] to the [`Nested`] overlay.
    pub fn operate(
        &mut self,
        layout: Layout<'_>,
        renderer: &Renderer,
        operation: &mut dyn widget::Operation,
    ) {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            layout: Layout<'_>,
            renderer: &Renderer,
            operation: &mut dyn widget::Operation,
        ) where
            Renderer: renderer::Renderer,
        {
            let mut layouts = layout.children();

            if let Some(layout) = layouts.next() {
                element.operate(layout, renderer, operation);

                if let Some((mut nested, nested_layout)) =
                    element.overlay(layout, renderer).zip(layouts.next())
                {
                    recurse(&mut nested, nested_layout, renderer, operation);
                }
            }
        }

        recurse(&mut self.overlay, layout, renderer, operation);
    }

    /// Processes a runtime [`Event`].
    pub fn on_event(
        &mut self,
        event: Event,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
        renderer: &Renderer,
        clipboard: &mut dyn Clipboard,
        shell: &mut Shell<'_, Message>,
    ) -> event::Status {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            layout: Layout<'_>,
            event: Event,
            cursor: mouse::Cursor,
            renderer: &Renderer,
            clipboard: &mut dyn Clipboard,
            shell: &mut Shell<'_, Message>,
        ) -> (event::Status, bool)
        where
            Renderer: renderer::Renderer,
        {
            let mut layouts = layout.children();

            if let Some(layout) = layouts.next() {
                let (nested_status, nested_is_over) =
                    if let Some((mut nested, nested_layout)) =
                        element.overlay(layout, renderer).zip(layouts.next())
                    {
                        recurse(
                            &mut nested,
                            nested_layout,
                            event.clone(),
                            cursor,
                            renderer,
                            clipboard,
                            shell,
                        )
                    } else {
                        (event::Status::Ignored, false)
                    };

                if matches!(nested_status, event::Status::Ignored) {
                    let is_over = nested_is_over
                        || cursor
                            .position()
                            .map(|cursor_position| {
                                element.is_over(
                                    layout,
                                    renderer,
                                    cursor_position,
                                )
                            })
                            .unwrap_or_default();

                    (
                        element.on_event(
                            event,
                            layout,
                            if nested_is_over {
                                mouse::Cursor::Unavailable
                            } else {
                                cursor
                            },
                            renderer,
                            clipboard,
                            shell,
                        ),
                        is_over,
                    )
                } else {
                    (nested_status, nested_is_over)
                }
            } else {
                (event::Status::Ignored, false)
            }
        }

        let (status, _) = recurse(
            &mut self.overlay,
            layout,
            event,
            cursor,
            renderer,
            clipboard,
            shell,
        );

        status
    }

    /// Returns the current [`mouse::Interaction`] of the [`Nested`] overlay.
    pub fn mouse_interaction(
        &mut self,
        layout: Layout<'_>,
        cursor: mouse::Cursor,
        viewport: &Rectangle,
        renderer: &Renderer,
    ) -> mouse::Interaction {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            layout: Layout<'_>,
            cursor: mouse::Cursor,
            viewport: &Rectangle,
            renderer: &Renderer,
        ) -> Option<mouse::Interaction>
        where
            Renderer: renderer::Renderer,
        {
            let mut layouts = layout.children();

            let layout = layouts.next()?;
            let cursor_position = cursor.position()?;

            if !element.is_over(layout, renderer, cursor_position) {
                return None;
            }

            Some(
                element
                    .overlay(layout, renderer)
                    .zip(layouts.next())
                    .and_then(|(mut overlay, layout)| {
                        recurse(
                            &mut overlay,
                            layout,
                            cursor,
                            viewport,
                            renderer,
                        )
                    })
                    .unwrap_or_else(|| {
                        element.mouse_interaction(
                            layout, cursor, viewport, renderer,
                        )
                    }),
            )
        }

        recurse(&mut self.overlay, layout, cursor, viewport, renderer)
            .unwrap_or_default()
    }

    /// Returns true if the cursor is over the [`Nested`] overlay.
    pub fn is_over(
        &mut self,
        layout: Layout<'_>,
        renderer: &Renderer,
        cursor_position: Point,
    ) -> bool {
        fn recurse<Message, Theme, Renderer>(
            element: &mut overlay::Element<'_, Message, Theme, Renderer>,
            layout: Layout<'_>,
            renderer: &Renderer,
            cursor_position: Point,
        ) -> bool
        where
            Renderer: renderer::Renderer,
        {
            let mut layouts = layout.children();

            if let Some(layout) = layouts.next() {
                if element.is_over(layout, renderer, cursor_position) {
                    return true;
                }

                if let Some((mut nested, nested_layout)) =
                    element.overlay(layout, renderer).zip(layouts.next())
                {
                    recurse(
                        &mut nested,
                        nested_layout,
                        renderer,
                        cursor_position,
                    )
                } else {
                    false
                }
            } else {
                false
            }
        }

        recurse(&mut self.overlay, layout, renderer, cursor_position)
    }
}